Nonwoven fabrics are used in absorbent articles, such as sanitary products and disposable diapers, cleaning products, such as wipes and wipers, and medical goods, such as masks, and such products employ nonwoven fabrics with a performance suitable for the purpose of the products and their intended location of use.
With absorbent articles, for example, it is necessary to employ nonwoven fabrics that are capable of expanding and contracting in response to bodily movement during wear or use, without creating an uncomfortable feeling for the user. Disposable diapers require nonwoven fabrics with high elasticity and strength sufficient to prevent tearing during extension, as well as excellent feel on the skin and liquid permeability.
Nonwoven fabrics exhibiting the desired performance in such absorbent articles are usually designed for each individual product and produced from a net or the like. From the viewpoint of production cost and environmental protection, therefore, it is preferred for a nonwoven fabric having the desired performance to be one that can be easily produced by modification of a commercially available nonwoven fabric, for example.
As an example of a nonwoven fabric with excellent resistance to liquid leakage, that can be produced from a commercially available nonwoven fabric, PTL 1 describes a method for producing a surface sheet for an absorbent article, wherein an upper layer is incorporated into the mesh section between a first roll with an irregular peripheral surface and a second roll with an irregular peripheral surface which has a shape that meshes with the irregular shape of the first roll, to form the upper layer into an irregular shape, and the upper layer is held by aspiration on the peripheral surface of the first roll while in the irregularly formed state while being laminated with a lower layer, the lower layer being bonded to the upper layer on the protrusions of the first roll. It also describes a surface sheet produced by the method.